1. Field of the Invention
The present invention generally relates to a semiconductor manufacturing apparatus and a control method thereof. More particularly, the present invention relates to a semiconductor manufacturing apparatus having a slit valve control system and to a method of controlling the operation of the slit valve so as to open and close a slit aperture formed between chambers.
A claim of priority is made to Korean Patent Application No. 2004-0064446, filed Aug. 16, 2004, the disclosure of which is hereby incorporated by reference in its entirety.
2. Description of the Related Art
Conventionally, a semiconductor manufacturing apparatus includes multiple process chambers disposed adjacent to each other. A manufacturing process is performed under vacuum in the process chambers. The apparatus further includes a treatment chamber to treat wafers, a load lock chamber to load and unload the wafers, and a transfer chamber to transfer the wafers. In general, the transfer chamber is disposed between the process chambers and the load lock chamber.
Each of the chambers described above has a slit aperture formed therein. The slit aperture is used to allow a wafer to pass into and out of the chamber. A slit valve opens and closes the slit aperture. Generally, the slit valve is operated by air pressure. The slit valve includes a valve plate and an actuator to operate the valve plate. An air source to provide pressure to operate the actuator is disposed thereabouts.
The slit valve operates when the pressure difference between the chambers is adjusted. When the pressure difference between the chambers is significant and the slit aperture is opened, problems may arise such as wafers moving within the chambers due to the pressure difference, which causes damage to the wafers, and/or damage to the vacuum pump due to rapid breakage of vacuum within the chambers.
In order to solve these problems, a slit valve is operated by regulating the pressure difference between the chambers. Japanese Laid-open Publication No. 1993-029263, for example, discloses a method of regulating the pressure differences.
The slit valve may also be manually operated to open and close the slit aperture. That is, although in general the slit valve operates automatically, if the semiconductor manufacturing apparatus interlocks during a manufacturing process or during maintenance, an operator may operate the slit valve manually.
When a chamber requires service, the chamber must be under atmospheric pressure prior to servicing the chamber. At this time, if there are wafers in an adjacent chamber and the operator unintentionally operates the slit valve, the wafers may move due to the pressure difference between the chambers, which can cause damage to the wafers and/or damage to the vacuum pump due to rapid breakage of vacuum within the chambers.